Why is sizeof (Point) equal to 8?

Question

I wrote some code and I get a weird integer value i: 8:

unsafe
        {
            int i = sizeof(Point);
        }

After checking the struct Point, I found these fields:

    public bool IsEmpty { get; }
    public int X { get; set; }
    public int Y { get; set; }

bit math: 32 + 32 + 1 = 65 bits, so> 8 bytes

So why does sizeof return 8 but not 9?

thank

+3

zzfima 05 june '15 at 6:28

2 answers

the framework implementation Point

only uses two attributes:

private int x;
private int y;

Empty

implemented as

[Browsable(false)]
public bool IsEmpty { 
    get {
        return x == 0 && y == 0;
    }
}

Two fields int

take 8 bytes - and you're fine.

+5

JimiLoe 05 june 15 at 6:49 am

Joey · Accepted Answer · 2015-06-05T06:30:53+0000

IsEmpty

is a property, not a field. Properties are just methods behind the scenes, so they are not part of the structure's size.